This is supposed to keep one from being pulled over for a noisy muffler. A wonderful side effect also keeps the extractor from leaking so it inadvertantly maintains power & fuel efficiency.
The stock design for lower header pipes that connect to the heater transfer cases have flanged sleeves for muffler gasket (donuts) and are made to slide on (and off). If (when) they move (like from backing into a curb, or dragging the muffler over a rock or steep gutter), it breaks the seal formed by the gasket and cops stop you for the noise.
A more sophisticated design uses bolted exhaust Flange gasket plates welded to the header and the transfer case exhaust pipe. They work well but are not as strong as the clamp shown below which just bolts on and is made from hardware store stuff.
The red thingie is 3 pieces plus 3 - 1/2 inch nuts that hold it together. It hooks over the transmission support and pulls the lower header pipes against the heat exchange pipe (so they won't move fore & aft) when the nuts are tightened. It can be tightened up enough to warp things, so employ some self control there.
- 12 inches of 1/2 inch all thread
- 10 inches of 1-1/2 x 1/8 iron strap,
- the strap around the header pipe is about 6 inches long by 16 gau. x 1 inch wide.
The blue bracket is the transmission support (comes w/ the car). Later bus designs have the support across the back of the engine below the header. The clamp there is the same idea, just shorter.
The orange thingie is a heavy hose clamp that loops around the muffler and the header pipe to reduce vibration. My muffler came with a bracket on the side to attach to something, but though it was 1/8 inch thick, it was spot welded to 20 gauge muffler tin. I tried an ordinary stainless hose clamp but it disappeared. The best one is a heavy hose clamp made from 3/4 x 1/16 stainless strap about 2 feet long, and a 5/16 inch bolt (so far so good, 11 yrs +).